1. Field
Example embodiments relate to apparatuses and methods for processing video signals. Also, example embodiments relate to apparatuses and methods for processing operations to separate and deinterlace luminance and chrominance signals using a single frame memory.
2. Description of Related Art
Scanning video signals in television systems are generally carried out in a progressive or interlaced scanning mode. The progressive scanning mode sequentially scans all horizontal scanning lines included in a given frame. In contrast, the interlaced scanning mode scans half of the horizontal scanning lines in a given frame at a time. For example, the interlaced scanning mode may first scan the odd-numbered scanning lines and then scan the even-numbered scanning lines.
FIG. 1A is a schematic diagram of an example interlaced scanning mode. Referring to FIG. 1A, a display apparatus using the interlaced scanning mode—such as an analog television set—displays one field at desired intervals (i.e., about every 60th of a second). For example, an analog television alternately scans the top field composed of the odd-numbered scanning lines (1, 3, 5, . . . , 477, and 479) and the bottom field composed of the even-numbered scanning lines (2, 4, 6, . . . , 478, and 480), each field being scanned about every 60th of a second. A single frame is composed of a combination of the top and bottom fields. Thus, the analog television displays one frame about every 30th of a second.
FIG. 1B is a schematic diagram of an example progressive scanning mode. Referring to FIG. 1B, a display apparatus using the progressive scanning mode—such as a computer monitor or digital television-displays one frame at desired intervals (i.e., about every 60th of a second). For example, the computer monitor or digital television sequentially scans all of the scanning lines (1-480) about every 60th of a second.
As such, the progressive and interlaced scanning modes process the scanning lines of a frame differently. Therefore, a display apparatus using the interlaced scanning mode cannot display an image in the progressive scanning mode. Similarly, a display apparatus using the progressive scanning mode cannot display an image in the interlaced scanning mode.
The present standards for television systems—such as NTSC (National Television System Committee), PAL (Phase Alternation Line), SECOM (Sequential Couleur Avec Memoire)—use the interlaced scanning mode. Thus, in order to watch a television that receives broadcasting signals transmitted by the NTSC, PAL, and/or SECAM systems using the interlaced scanning mode, the television must employ a display apparatus operable in the interlaced scanning mode. However, recent display apparatuses are mostly operable in the progressive scanning mode. Therefore, there is a need to convert interlaced scanning video signals into progressive scanning video signals so that a display apparatus operable in the progressive scanning mode may display the interlaced scanning video signals.
FIG. 2 is a block diagram showing a conventional video signal processing apparatus. Referring to FIG. 2, the video signal processing apparatus 100 include a first frame memory 110, a Y/C separator 120, a color demodulator 130, a second frame memory 140, and a deinterlacer 150.
The first frame memory 110 accepts and stores a composite interlaced video signal (CIVS). The CIVS is also called a color, video, blanking, and sync (CVBS) signal.
The Y/C separator 120 accesses the first frame memory 110 and separates Y and C signals from the CIVS. Here, the Y represents a luma or luminance signal and C represents a chroma or chrominance signal. The Y/C separator 120 provides the luma (Y) signal to the second frame memory 140 and provides the chroma (C) signal to the color demodulator 130.
The color demodulator 130 receives the chroma (C) signal and determines horizontal (U) and vertical (V) signal components (or signals) of the chroma (C) signal. The color demodulator 130 provides the horizontal (U) and vertical (V) signals to the second frame memory 140.
The second frame memory 140 receives the luma (Y) signal from the Y/C separator 120; receives the horizontal (U) and vertical (V) signals from the color demodulator 130; and stores the luma (Y) signal, the horizontal (U) signal, and the vertical (V) signal.
The deinterlacer 150 reads data from the second frame memory 140 and then generates an interpolated Y signal (referred to in this application as the Y′ signal), an interpolated U signal (referred to in this application as the U′ signal), and an interpolated V signal (referred to in this application as the V′ signal). Then, the deinterlacer 150 outputs a component progressive video signal (CPVS) composed of the Y, U, V, Y′, U′, and V′ signals.
The video signal processing apparatus 100 shown in FIG. 2 separates the Y and C signals from the CIVS using the Y/C separator 120. And the video signal processing apparatus 100 generates the CPVS signal using the deinterlacer 150.
However, as illustrated in FIG. 2, the video signal processing apparatus 100 uses the first frame memory 110 for Y/C separation and the second frame memory 140 for deinterlacing. Using two frame memories in the video signal processing apparatus 100 increases cost. Further, since the procedure for processing a video signal requires accessing both the first frame memory 110 and the second frame memory 140, it takes a long time to process the video signal.